1. Field of the Invention
This invention relates to a method for displaying images on a display and a system for implementing the method.
The present application claims priority from Japanese Application No. 2000-361128, the disclosure of which is incorporated herein by reference for all purposes.
2. Description of the Related Art
Information technology devices having a display for displaying a variety of information, such as a personal computer, a portable telephone and a navigation system, have achieved widespread use in recent years.
For example, personal computers display vector-mode graphic data, e.g. a map image, stored on storage medium such as a hard disk (HD) and a CD-ROM, on the display for users to avail themselves of. A display with a more detailed image typically requires a larger amount of data, which tends to increase the plotting time to display the image on the display.
In a large amount of data of an image to be displayed, it takes much time to shift the screen during scrolling. This produces the problem of interfering with the smooth screen operation.
Particularly, when an image of a large amount of data is displayed on an information technology device having a small memory capacity for displaying images, such as a portable telephone, the information technology device tends to take an extremely long time to display the image.
In this case, user's requests regarding the use of the image information vary in different cases, for example, when a highly precise image is required although it takes much time to display the image, and when a faster display speed is required regardless of the precision of the image.
However, various conventional kinds of information technology devices display a vector image on the display uniformly regardless of the amount of image data. Thus it is impossible for the conventional information equipment to respond to the varied needs of users in different cases.